In the technology proposed in Japanese Unexamined Patent Application Publication No. 2003-318441, recesses and protrusions are formed on the surface of a sapphire substrate and a semiconductor light-emitting layer is then formed on the uneven surface. The uneven surface is shaped so that crystal defects are not caused in the semiconductor light-emitting layer. Since light emitted from the light-emitting layer scatters or diffracts on the uneven surface, high external quantum efficiency is obtained.